Deceleration of a submerged towed vessel



Sept. 28, 1965 MICHIMASA ENDO 3,208,423

DECELERATION OF A SUBMERGED TOWED VESSEL Filed Oct. 18, 1963 INVENTOR. MICHIMASA ENDO United States Patent Japan, assignor to Ponca City, Okla, a corpo- This invention relates to a submersible tow having ballast tanks in the fore and after bodies of the tow or vessel, said tanks being in communication with an air storage means through blowoff valves and each of said tanks having an exhaust port. In a submerged condition said vessel can be given any desired longitudinal inclination by exhaustion of either one of said ballast tanks.

An object of this invention is to provide means enabling a submersible tow which has relatively little underwater resistance to be controlled readily, e.g. for quick stoppage.

Other objects and advantages will be apparent from the following detailed description.

Now the present invention will be explained With reference to an embodiment thereof illustrated in the accompanying drawings, in which:

FIGURE 1 is a plan showing the internal structure of a submersible tow according to the present invention; and

FIGURE 2 is a side elevational view of the vessel out of motion.

The numeral 71 indicates a hull provided with a fixture for towline 2 on the fore body thereof and with the tail units 3 after, the fore and after bodies of the hull being further equipped, respectively, with ballast tanks 4 and 5, which have exhaust ports 6 and 7, respectively.

Said ballast tanks 4 and communicate through appropriate lines and blowoif valves 8 and 9 to air storage chambers 10 and 11, respectively, in such manner that by operating said blowotf valves 8 and 9 water inside the tanks 4 and 5 can be exhausted by displacement with a1r.

The submersible tow constructed in accordance with this invention, as above described, can be stopped quickly, when the tugboat ceases towing by operating the blowotf valve 8 to exhaust by air the fore ballast tank 4, whereby the hull 1 is subjected to a buoyancy produced by the exhaustion of the fore ballast tank 4, in addition to its own reserve buoyancy, and as a result, the stem of the vessel rises high above the water level 12 while the stern settles downwardly to the bottom of the water 13. Thus in FIGURE 2 the hull 1 drags the land structure beneath the water and the vessel comes to a quick stop.

The vessel is stopped as promptly when the depth of the water is much greater, preventing dragging the land structure, since the hull 1 is abruptly inclined longitudinally by the foregoing procedure. This inclination from horizontal correspondingly increases the resistance applied to the hull, and resistance encountered rapidly shows and terminates the forward speed of the vessel.

After the hull 1 has ben stopped as above, the blowolf valve 9 is operated to exhaust by air the after ballast tank 5, thereby to restabilize the hull 1 horizontally.

As the submersible tow according to the invention has been described above, the fore and after bodies of the vessel are provided with ballast tanks, each having an exhaust port. The air storage apparatus communicating through blowoff valves to said tanks allow for the exhaustion of a corresponding ballast tank by operating said blowoff valves. The control of the tanks causes the hull to incline sharply in the longitudinal direction by means of the buoyancy produced by the exhaustion of said tank and by the reserve buoyancy of the hull itself, thereby causing one end of the vessel to drag on the bottom beneath the water, or, where the depth of the water is much greater, to subject the hull to abruptly increased underwater resistance by the sharp inclination thereof. Thus, while an ordinary submersible tow usually requires a prolonged period of time for stoppage, because of relatively small underwater resistance it encounters, the present invention enables the vessel to be stopped readily and quickly. This invention is adaptable for large submersible tows which are subject to particularly great forces of inertia.

What is claimed is:

A method of terminating the forward movement of a towed submerged vessel, which is fitted with ballast tanks in the fore and aft portions of the hull, ballast exhaust ports in each of the ballast tanks, and means for expelling ballast selectively from the ballast tanks, comprising the step of:

deballasting the forward ballast tank such that the buoyancy imparted thereby will cause an angle of forward inclination to the vessel such that the forward water resistance will be increased to thus increase the deceleration of the vessel.

References Cited by the Examiner UNITED STATES PATENTS 1,373,329 3/21 Hoar 114-16.3 3,074,321 1/63 Draim et al. 114-235 FOREIGN PATENTS 885,079 5/43 France.

FERGUS S. MIDDLETON, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,208,423

September 28, 1965 Michimasa Endo It is hereby certified that error appears in the above numbered petent requiring correction and that the said Letters Patent lhould read as corrected below.

Column 1, line 30, for "71" read 1 column 2 line 5, for "shows" been slows line 7 for "ben" read Signed and sealed this 16th day of' August 1966.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents 

